堅

nucleus

holding on to

firm (market)

steady

sound

solid

strong defense

honest

center fielder

square

America

medium-sized enterprise (business, firm)

discreet

tight-lipped

tight-lipped

underworld

hardwood

confirmation (rite)

chaste woman

sound business

robust

straight-laced person

honest

nut

possessed of a strong sense of duty

very cautious (watchful, vigilant)

sophism

underworld

solidly built person

hard wood

being of firm (unshakable) faith and strict practice

(a fortress being) impregnable

stable (market) after having bottomed out

formal

formal

(the Christian sacrament of) confirmation

impregnable fortress

stronghold

strong fortress

strong determination

iron purpose

stronghold

hard

prudish

hard biscuits

strength

dogged perseverance

indomitable perseverance

of strict morals (moral principles)

firm and solid

a wholesome household can not be disturbed from the outside

pachycephalosaur (any dinosaur of infraorder Pachycephalosauria)

being faithful to one's principles

hard charcoal

snow with a frozen crust on top

firm and unyielding

chaste (usu. to one's husband)

perseverance

firm tofu

firm and solid

solid